The following is an overview of what's new in 0.4.0:
* Curse of Monkey Island (comi) support (experimental)
* Added support for the EGA versions of Loom, Monkey Island and Indy3
* Improved music support in Indy3 and the floppy versions of Monkey Island
* Many Simon the Sorcerer 1 & 2 improvements and fixes
* Very pre-alpha Beneath a Steel Sky code. Don't expect it to do anything (in fact it is disabled in the 0.4.0 release, but you can get it by compiling ScummVM yourself).
* Even more pre-alpha support for enhanced versions of V2 SCUMM games (Maniac Mansion and Zak)
* Preliminary support for early Humongous Entertainment titles (very experimental)
* New debug console and several GUI/Launcher enhancements
* New Save/Load code (easier to expand while retaining compatibility)
* Dreamcast port now works with new games added for 0.3.0b
* New official PalmOS port
* Various minor and not so minor SCUMM game fixes
* Large memory leak fixed for The Dig/COMI
* SMUSH code optimised, frame dropping added for slower machines
* Code cleanups